Baffle elements have long been used to limit the amount of movement of the liquid in a reservoir. Baffles have been incorporated into ink jet print head cartridges to reduce the mass of the liquid ink allowed to slosh unimpeded by the containing walls of the ink supply reservoir. The use of baffles in ink reservoirs has been disclosed, for example, in U.S. Pat. Nos. 5,408,257; 4,631,558; 4,484,202; and 4,463,362. Prior baffles incorporated into ink supply reservoirs are integral with, or permanently attached to, at least one of the walls forming the ink supply reservoir.
U.S. Pat. No. 5,408,257 discloses an ink tank, or reservoir, having an inner wall portion or member attached to the bottom face of a sub-tank, and arranged in a diagonal direction to prevent ink in the sub-tank from vibrating greatly.
U.S. Pat. No. 4,631,558 discloses an ink liquid reservoir mounted on a reciprocating cartridge in an ink jet system printer having a plurality of standing plates that are disposed in the ink liquid reservoir in a manner such that the top free edge of the standing plates are separated from the sealing wall of the ink liquid reservoir. The standing plates are secured to the bottom wall of the ink liquid reservoir.
U.S. Pat. No. 4,484,202 discloses an ink reservoir containing a plurality of vertically arranged baffles, or plate elements. The plate elements create a series of narrow compartments. An opening is provided in each baffle plate to enable flow of ink fluid among the separate compartments formed by the baffles. The baffles constrain excessive movement of the ink into narrow spaces as the print head is moved in a lateral direction by an appropriate carriage during the printing operation.
U.S. Pat. No. 4,463,362 discloses an ink reservoir which includes a plurality of baffles to provide individual ink tanks for print heads and to prevent or substantially minimize the sloshing motion of the ink as the reservoir is accelerated and decelerated during the printing operation. The baffles are in the form of plates extending from the front wall to the rear wall of the reservoir and are formed as an integral part of the reservoir at the floor thereof. A plurality of apertures are provided in the baffle plates near the bottom thereof and located near the rear wall of the reservoir for equalizing the levels of ink in the respective baffle-formed chambers or tanks.
Regardless of whether the baffles are formed integral with the ink supply reservoir body, or are later attached to one or more of the walls of the ink reservoir body, the baffles form rigid structures which generate shock waves within the ink as the ink is sloshed from side-to-side in the ink supply reservoir. Furthermore, ink supply reservoirs having rigidly mounted baffles are complex to manufacture, in that either the baffles must be formed as a part of the reservoir body during the molding process, or the baffles are separately molded from the reservoir body and attached to one or more walls of the ink supply reservoir after the ink supply reservoir is molded, thereby requiring additional steps in its manufacture.